I am using the checkbox in listtile in flutter(v3.0.4) like this:
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: Card(
child: ListTile(
visualDensity: VisualDensity(vertical: 3), // to expand
title: Text("dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"),
leading: Checkbox(
value: true,
onChanged: (bool? value) {
if (value!) {}
})))) // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
when the listtile text expand, the checkbox always align to the top like this:
what should I do to make the checkbox always align to the center of vertical in the card component?
Try
Center(child: checkbox)
Or
Centet(child:
Column(
mainAxisSize:MainAxisSize.min,
mainAxisAlignment:MainAxisAlignement.center,
crossAxisAlignment: crossAxisAlignment.Center,
Children: [ Checkbox()]
Related
When I restart this code in Visual Studio autofocus is working as well as keyboard is showing. When I close the visual studio and re open the app in android emulator the keyboard is not showing but auto focus is working (Cursor is showing).
But its work in android 5 perfectly.
My code:
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: TextField(
autofocus: true,
)
),
);
}
}
Can anyone fix this? Thank you.
Try the following code:
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final FocusNode focusNode = FocusNode();
#override
void initState() {
super.initState();
focusNode.requestFocus();
}
#override
void dispose() {
focusNode.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: TextField(
focusNode: focusNode,
autofocus: true,
),
),
);
}
}
I'm currently working on a Flutter project. I have been given Icons by the designer.
One of the Icons looks like this
Now I'd like to fill the inside of the Icon with color so that it looks like this
How can I achieve this in flutter? I really tried a lot. Like using ClipRect and other Classes. But none gave the desired results.
Try this one.
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
bool _isBluetoothOn = false;
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
IconButton(
onPressed: () async {
print(_isBluetoothOn);
setState(() {
_isBluetoothOn = !_isBluetoothOn;
});
print(_isBluetoothOn);
},
icon: Icon(
_isBluetoothOn ? Icons.favorite : Icons.favorite_border,
color: Colors.greenAccent,
size: 40,
),
),
],
),
),
);
}
}
You can simply ask designer for filled icons too and show them when they are clicked.
So it goes like this:
if button clicked:
show filledIcon
else:
show unfilledIcon
You can code that in Flutter like:
icon:clicked? Icon(filledIcon):Icon(unfilledIcon)
This is the easiest way to do this.
i try to pass a variable "int counter = 0;" in a state widget ,but i don't know why i can't retrieve it , the App return me as "Null", I passed all the variables into the constructor though , (class MyHomePage extends StatefulWidget).
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title, this.counter}) : super(key: key);
final String title;
int counter= 0;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
void _incrementCounter() {
setState(() {
widget.counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'${widget.counter}',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
Thank you for your help
Widgets (including StatefulWidgets) should always be immutable, should not change over their lifetime. In fact, you should see a warning if you try to add a non-final variable to the StatefulWidget, since it is a subtype of Widget, which has the #immutable annotation.
It is very rare that any logic actually takes place inside a StatefulWidget subclass. Instead, all the state and associated logic should be in the State class.
You should move counter into the state class like this:
class MyHomePage extends StatefulWidget {
final String title;
const MyHomePage({Key key, this.title}) : super(key: key);
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int counter = 0;
void _incrementCounter() {
setState(() {
counter++;
});
}
// the rest is the same, except using counter instead of widget.counter
}
Lets first analyze code
home: MyHomePage(title: 'Flutter Demo Home Page'),
// You did not pass integer to the counter field, dart pass null to counter field
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title, this.counter
/* here null will be initialized to the counter field */
}) : super(key: key);
final String title;
int counter= 0; // now it is null
#override
_MyHomePageState createState() => _MyHomePageState();
}
So for this reason you get null
How to correctly pass in your scenario:
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title, this.counter=0}) : super(key: key);
final String title;
int counter;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
void _incrementCounter() {
setState(() {
widget.counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'${widget.counter}',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
By default, Flutter respects the SafeArea around the notch.
After SystemChrome.setEnabledSystemUIOverlays([]) (to remove time, overlay etc.) then setting SafeArea to false on all sides, there is still a blank area around the notch:
How can I make the app render without considering the notch? i.e. the AppBar should display under the black notch area.
Code:
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
SystemChrome.setEnabledSystemUIOverlays([]);
return SafeArea(
top: false,
bottom: false,
left: false,
right: false,
child: Scaffold(
resizeToAvoidBottomInset: false,
appBar: AppBar(title: Text(widget.title)),
body: Center(
child: Text(
'hello stack overflow',
),
),
),
);
}
}
Is there a way to make Scaffold.bottomSheet partly transparent (like for a notch that shows the body content behind it)? I noticed that even adding just Text implicitly puts a white background (Material?) below it, and I think this is not configurable.
class MyHomePage extends StatefulWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
color: Colors.blue,
child: // ...
),
bottomSheet: Text('This is a bottom sheet'),
);
}
}
FWIW, Scaffold.bottomNavigationBar supports being semi-transparent (e.g. you can have a notch around FAB).
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
home: MyHomePage(title: 'Flutter Demo Home Page'),
theme: ThemeData(
bottomSheetTheme: BottomSheetThemeData(
backgroundColor: Colors.black.withOpacity(0.5)),
),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.blue,
appBar: AppBar(
title: Text(widget.title),
),
body: Center(),
bottomSheet: Container(
height: 40,
width: MediaQuery.of(context).size.width,
child: Center(child: Text('semi transparent bottom sheet :)', style: TextStyle(color: Colors.white),))
),
);
}
}
this was previously posted